h5,
body,
p {
    margin: 0;
    padding: 0;
}

.nav-bar {
    display: flex;
    width: 300px;
    height: 40px;
    background-color: beige;
    justify-content: space-between;
    align-items: center;
}

.nav-bar .left,
.nav-bar .right {
    width: 50px;
    height: 100%;
    border: 1px solid #000;
    text-align: center;
    line-height: 40px;
}

.nav-bar .center {
    flex: 1;
    height: 100%;
    border: 1px solid #000;
    text-align: center;
    line-height: 40px;
}